Many documents are known describing processes for the conversion of (gaseous) hydrocarbonaceous feedstocks, especially methane, natural gas and/or associated gas, into liquid products, especially methanol and liquid hydrocarbons, particularly paraffinic hydrocarbons. In this respect reference is often made to remote locations and/or off-shore locations, where no direct use of the gas is possible. Transportation of the gas, e.g. through a pipeline or in the form of liquefied natural gas, is not always practical. This holds even more in the case of relatively small gas production rates and/or fields. Reinjection of gas will add to the costs of oil production, and may, in the case of associated gas, result in undesired effects on the crude oil production. Burning of associated gas has become an undesired option in view of depletion of hydrocarbon sources and air pollution.
In WO 94/21512 a process for the production of methanol has been described from an off-shore natural gas field using a floating platform.
In WO 97/12118 a method and system for the treatment of a well stream from an off-shore oil and gas field has been described. Natural gas is converted into syngas using pure oxygen in an autothermal reformer, a combination of partial oxidation and adiabatic steam reforming. The syngas (comprising a considerable amount of carbon dioxide) is converted into liquid hydrocarbons and wax.
In WO 91/15446 a process is described to convert natural gas, particularly remote location natural gas (including associated gas), in the form of normally liquid hydrocarbons suitable for fuel use via methanol/dimethyl ether.
In U.S. Pat. No. 4,833,170 a process is described for the production of heavier hydrocarbons from one or more gaseous light hydrocarbons. The light hydrocarbons are converted into syngas by autothermal reforming with air in the presence of recycled carbon dioxide and steam.
The process for producing normally gaseous, normally liquid and normally solid hydrocarbons from a hydrocarbonaceous feedstock produces during normal operation uses a high amount of energy. This means that in this process any unit operation requiring energy for carrying out its required function this energy is generated and/or provided by other unit operations. This implies also that this production process is not integrated or combined with other systems for temporarily providing heat and power. This is even more true when the production process is carried out at remote and/or stranded gas locations. Although the process for producing hydrocarbons also produces heat and power, the start (or restart) of this process requires energy which is not (at any time) available. It would be useful to provide a method to start up such a process at low (operational) costs.